Bug Description

Some hardware volume drivers secure volumes based on the name of the initiator. When the connection is prepared, an ip address is sent in, but the volume driver has no way of knowing what initiator the iscsi connection will come from. There needs to be some way for the driver to get the right initiator for the instance.

This could be done with a callback, but it is easiest to add the parameter to initialize_connection.

Some volumes need to know the name of the initiator that will be
connecting to the iscsi volume. This adds a call down to the hypervisor
driver to get the ip and the initiator name for the vm before calling
initialize connection. This connection is passed down to the volume
driver so that it can be used to authenticate when the hypervisor
tries to connect to the volume.